The present invention relates generally to water softeners and more specifically to a salt grid placed within a brine tank in a water softening system.
Water softening systems are well known and typically involve a pressurized water treatment device in which hard water is passed through a bed of cation exchange media (either inorganic or synthetic organic) for the purpose of exchanging calcium and magnesium ions for sodium or potassium ions, thus producing a softened water which is more desirable for laundering, bathing and dish washing. Water softeners typically consist of a resin tank containing an ion exchange material such as zeolite or resin beads.
Water softening capacity must be regenerated at intervals depending on the hardness of the water and the capacity of the softener. Regeneration of the water softener is typically accomplished by flushing brine (common salt solution) through the exchange material to replace collected calcium and magnesium ions with sodium ions. The brine solution is provided from a brine tank and, after flushing through the resin tank, the flush brine waste is disposed of properly.
Brine tanks are typically constructed large enough to hold a large volume of salt so that the water softening system may undergo many regeneration cycles without having to replenish the salt in the brine tank. At least a portion of the salt contained in the brine tank is in contact with water which causes the salt to dissolve and form the saturated brine solution which collects at the bottom of the brine tank. It is undesirable for any salt crystals or pellets to be transmitted with the brine solution to the ion exchange medium. It has thus been common and known in the art to provide a xe2x80x9csalt gridxe2x80x9d to support the granular salt at a fixed level above the bottom of the brine tank, but below the top level of the brine solution in the brine tank. The salt grid typically contains openings therein which allow dissolved salt to pass therethrough but prevent passage of solid crystals or pellets. In this manner, a saturated brine solution develops below the grid without any significant amount of undissolved salt being transmitted with the saturated brine solution when the brine solution is drawn from the bottom of the brine tank through the brine well.
Many different salt grids are commercially available. Some designs involve salt grids having multiple parts which require assembly before installation in the brine tank. Other arrangements involve unitary, or one-piece salt grids which can be installed directly into the brine tank. One known salt grid design allows nesting of multiple salt grids for convenient low volume shipping.
One problem with known salt grids is that dirt included with the salt passes therethrough and settles at the bottom of the brine tank. In turn, when saturated brine is drawn into the brine well the dirt is drawn therewith and may plug the brine well, close off the entrance to the brine well, plug control components such as injectors, and may foul the resin in the resin tank. As a result, the brine well cannot properly draw the saturated brine from the bottom of the tank, thereby limiting or entirely preventing regeneration of the resin. Therefore, once a substantial amount of dirt accumulates at the bottom of the brine tank, the brine tank must be cleaned, which is a tedious and undesirable task.
An additional problem with known salt grids is that they allow only a single volume of saturated brine to form in the brine tank below the salt grid, and this amount of brine solution may not be varied by the user when regenerating the resin tank. This is due to the fact that known salt grids support salt only at a single, fixed location above the bottom of the brine tank.
It is desirable to provide a salt grid for a brine tank which addresses the problem of dirt accumulation at the bottom of the brine tank, allows less frequent cleaning of the brine tank, and allows a lower quality (higher dirt content) salt to be used in the brine tank without requiring more frequent cleaning thereof.
It is further desirable to provide a salt grid that allows the user to vary the water level relative to the salt grid and to vary the position of the salt grid relative to the bottom of the brine tank in order to adjust the volume of saturated brine that forms in the brine tank below the salt grid.
The present invention is a salt grid having an upper surface of varying height which allows dirt passing through the salt grid to be collected in a localized area in the bottom of the brine tank. The brine well, which transfers brine solution from the brine tank to the resin tank, is positioned so that it draws saturated brine at a location spaced away from the localized area where dirt collects at the bottom of the brine tank. The present invention also provides leg extensions which may be affixed to the supporting legs of the salt grid to further raise the salt grid relative to the bottom of the brine tank to facilitate the formation of a greater volume of saturated brine in the brine tank below the salt grid.
In one form thereof, the present invention is a salt grid for supporting salt above at least a portion of the saturated brine solution in the brine tank. The salt grid comprises first and second platforms which are disposed at first and second elevational levels, respectively within the brine tank. The platforms provide a surface which supports the salt which is used to create the saturated brine solution. At least one of the platforms includes openings therein for permitting dissolved salt to flow therethrough, thereby increasing the concentration of the brine in the solution and forming a saturated brine. The first and second platforms are connected to one another and together they define an outer periphery of the grid. The grid spans an interior area of the brine tank defined by the inner walls of the brine tank. That is, the outer periphery of the grid contacts the inner walls of the brine tank providing a barrier for the salt. Integral legs depend from the first and second platforms to support the salt grid above the bottom of the brine tank.
The water level within the brine tank can thus be selected so that the water engages the salt supported on the lower platform, but not the salt supported on the upper platform. As salt dissolves and dissolved salt passes through the openings and into the saturated brine solution, dirt passes into the brine solution as well. However, the dirt settles in a localized area beneath that portion of the grid which is engaged by the water, typically on one side of the brine tank. The brine well is then placed on the opposite side of the brine tank so that when saturated brine is drawn therefrom, the dirt is not drawn therewith.
In another form thereof, the present invention is a salt grid having integral legs depending from the underside of the first and second platforms as described above. Leg extensions are attached to the integral legs, where the leg extensions support the salt grid and raise the salt grid a further distance from the bottom of the brine tank, allowing a larger volume of saturated brine to form in the brine tank beneath the salt grid.
Various configurations of the multi-level grid of the present invention are envisioned, the basic principle being that the water, or brine below the grid will engage the grid at a location away from the brine valve tube so that dirt drawn from the brine tank with the brine solution is minimized. One configuration of a salt grid in accordance with the present invention includes two generally planar, horizontally disposed platforms and a third sloping platform disposed therebetween, connecting the first and second platforms.
One advantage of such an arrangement is that the water level below the grid may be adjusted to accommodate higher salt settings (i.e. larger volume of brine below the salt grid). For example, the volume of brine solution below the salt grid may be increased because of the available space existing below the upper platform of the grid. By contrast, prior art salt grids offer no room to adjust the brine level.
Another advantage of the present invention is that leg extensions may be attached to the integral salt grid legs to further raise the salt grid from the bottom of the brine tank, allowing a larger volume of brine solution to form below the salt grid and therefore accommodating a higher salt setting.
A further advantage of the present invention is that it reduces the intervals between which the brine tank must be cleaned. By providing a salt grid which deposits the dirt contained in the salt in a localized area at the bottom of the brine tank, a larger volume of saturated brine solution can be drawn from the brine tank without the brine well becoming plugged with dirt. It has been found that a significant increase in the amount of dirt accumulated in the bottom of the tank can be allowed if the dirt is contained in a localized area as is provided by the present invention.
Still another advantage of the present invention is that the third sloping platform of the salt grid helps prevent xe2x80x9cbridging.xe2x80x9d Bridging is an undesirable phenomenon in which salt positioned above the salt grid develops a hard, cement-like consistency so that further dissolution of salt through the grid is prevented. Bridging typically occurs when the salt stagnates above the grid. The salt grid of the present invention reduces bridging because salt is encouraged to slide down the sloping surface of the salt grid of the present invention due to gravitational forces. In this manner, the salt grid of the present invention encourages more movement of the salt supported by the salt grid, which in turn avoids the bridging effect.
Yet another advantage of the present invention is that it allows an inexpensive salt (higher dirt content) to be used without requiring increased cleaning of the brine tank vis-à-vis prior art brine tanks. This is so because the salt grid of the present invention causes the dirt to be collected in a localized area and therefore allows a larger quantity of dirt to be collected between cleanings of the brine tank.